BLACK SKIMMER. 
227 
times are their hours of rest, and I believe of sleep, as, although partially 
diurnal, and perfectly able to discern danger by day, they rarely feed then, 
unless the weather be cloudy. On the same sands, yet apart from them, 
equal numbers of our Black-headed Gulls may be seen enjoying. the same 
comfort in security. Indeed, the Skimmers are rarely at such times found 
on sand or gravel banks which are not separated from the neighbouring 
shores by some broad and deep piece of water. I think I can safely venture 
to say that in such places, and at the periods mentioned, I have seen not 
fewer than ten thousand of these birds in a single flock. Should you now 
attempt to approach them, you will find that as soon as you have reached 
within twice the range of your long duck-gun, the crowded Skimmers 
simultaneously rise on their feet, and watch all your movements. If you 
advance nearer, the whole flock suddenly taking to wing, fill the air with 
their harsh cries, and soon reaching a considerable height, range widely 
around, until, your patienee being exhausted, you abandon the place. When 
thus taking to wing in countless multitudes, the snowy white of their under 
parts gladdens your eye, but anon, when they all veer through the air, the 
black of their long wings and upper parts produces a remarkable contrast to 
the blue sky above. Their aerial evolutions on such occasions are peculiar 
and pleasing, as they at times appear to be intent on removing to a great 
distance, then suddenly round to, and once more pass almost over you, flying 
so close together as to appear like a black cloud, first ascending, and then 
rushing down like a torrent. Should they see that you are retiring, they 
wheel a few times close over the ground, and when assured that there is nc 
longer any danger, they alight pell-mell, with wings extended upwards, but 
presently closed, and once more huddling together they lie down' on the 
ground, to remain until forced off by the tide. When the Skimmers repose 
on the shores of the mainland during high water, they seldom continue long 
on the same spot, as if they felt doubtful of security ; and a person watching 
them at such times might suppose that they were engaged in searching for 
food. 
No sooner has the dusk of evening arrived than the Skimmers begin to 
disperse, rise from their place of rest singly, in pairs, or in parties from 
three or four to eight or ten, apparently according to the degree of hunger 
they feel, and proceed in different directions along parts of the shores pre- 
viously known to them, sometimes going up tide-rivers to a considerable 
distance. They spend the whole night on wing, searching diligently for 
food. Of this I had ample and satisfactory proof when ascending the St. 
John river in Bast Florida, in the United States schooner Spark. The 
hoarse cries of the Skimmers never ceased more than an hour, so that I 
could easily know whether they were passing upwards or downwards in the 
